Extension Update from Jenny Rees

Extension Update from Jenny Rees – October 2

Yield Monitors:  Harvest is rapidly progressing!  Dr. Joe Luck wrote an article in this week’s CropWatch regarding making sure your yield monitor is collecting accurate information.  Here are a few pointers he shares: “The first item on the yearly checklist should be verifying that firmware is up to date on the in-cab monitor and your GPS system. This may require a check with your dealership or a visit to the company website. System software needs to be checked every year to make sure you’re running a current version.  Perhaps the most critical need is to calibrate the yield monitor as it affects yield estimates across all of your fields. While some operators use calibrations stored in the display from previous years (always double check to see how well previous calibrations are performing), most will need to perform new calibrations. For each calibration, try to conduct separate loads that span the variability (high to low) that you may expect to see when harvesting fields. Generally you can change combine speed or header cut width to vary crop flow through the machine to create this variation while calibrating. (See this week’s http://cropwatch.unl.edu for a diagram explaining calibration).

In general only 3,000 lb to 6,000 lb of grain are needed for each of these calibration loads. Harvesting a full semi-load of grain per calibration load point won’t necessarily improve calibration accuracy. Some yield monitors may only allow a two-point calibration, so it’s best to try and calibrate for a point of high flow, then one for a lower flow rate through the machine.

Remember that separate calibrations are needed for different crops (e.g., corn or soybeans) and accuracy will generally improve when calibrating for significant moisture variability for a crop (e.g., high and low moisture corn). If you’ve adopted a more recently commercialized optical yield monitor system (such as available from CLAAS, Trimble, and Raven, for example), test weight measurements become even more crucial when you change between different hybrids and crops.  In the end, remember that most well calibrated yield monitors should be able to estimate yields within 1% to 3% on a full-field basis. When looking at the sub-field scale, you’re likely to see errors exceeding 3%.”

Farm Finance and Ag Law Clinics:  Openings are available for one-on-one, confidential farm finance and ag law consultations being conducted across the state each month. Clinic sites and dates include:  Grand Island on Oct. 6; Norfolk Oct. 12; North Platte Oct. 13; Lexington Oct. 20; Fairbury Oct. 25; and Norfolk Oct. 31.  An experienced ag law attorney and ag financial counselor will be available to address farm and ranch issues related to financial planning, estate and transition planning, farm loan programs, debtor/creditor law, water rights, and other relevant matters. They offer an opportunity to seek an experienced outside opinion on issues affecting your farm or ranch.  To sign up for a clinic or to get more information, call Michelle at the Nebraska Farm Hotline at 1-800-464-0258.  The Nebraska Department of Agriculture and Legal Aid of Nebraska sponsor these clinics.

Stalk and Ear Rots:  Since late August/early September, anthracnose top die-back of corn caused by Colletotrichum graminicola has been observed in many fields.  Symptoms include upper portions of plants turning brown while the lower-mid portion of the plants remain green.  We’re also seeing stalk rot setting in corn plants.  To determine percent stalk rot for planning harvest and avoiding too much downed corn, I use a pinch test.  Take your thumb and first finger and pinch 20 plants in a row at the first or second internode above the soil line (use the same internode on all plants).  Determine a percent of the number that easily crush out of 20 plants with ears and repeat this in several areas of the field. 

The past few weeks I’ve calls regarding ear rots in corn.  Damage to corn ears from insects such as western bean cutworm and also hail can allow for secondary pests like the tiny black beetles some have asked about.  It also can allow for colonization of a number of Fusarium fungi or Gibberella zeae which is causing the white/pink cottony growth some are seeing.  The presence of these fungi may result in mycotoxins such as fumonisin, vomitoxin (DON), and/or zearalenone but does not always mean a mycotoxin is present. 

Another common ear rot being seen in fields right now is Diplodia (Stenocarpella) in which the fungal growth begins at the base of the ear with cottony white/gray fungal growth that spreads rapidly across the ear.  This fungus can also produce small, black reproductive structures on kernels that are raised and can feel rough to touch.  Often diplodia is more common in humid and/or wet falls with hybrids that have tight husks and when ears are upright longer.  This particular disease causes the kernels to be lightweight and there aren’t mycotoxins associated with the fungus causing this disease. It can be a problem in the bin reducing grain quality.  Corn harvested from fields with widespread ear rot diseases shouldn’t be stored long term as fungi can continue to grow in storage and reduce grain quality.  Cooling grain below 50F as quickly as possible (store at 30F) and drying grain quickly to less than 15% moisture (below 13% for storage through the following summer) minimizes fungal growth.

Natural needle drop will begin soon:  Evergreens retain one to three year old needles. Natural needle drop typically begins in September with interior needles suddenly and uniformly turning yellow from the top of the tree to the bottom. These yellow needles are easily knocked off of the tree by hand, wind or rainfall. Natural needle drop is just that:  natural and not of any concern. As a rule, pines hold their needles for two to three or more years and spruce trees hold needles five to seven years. Natural needle drop is most noticeable on white pines.

Perennial broadleaf weed control is most effective with spot treatments of herbicides applied during fall. It is best to wait until after the first light frost to begin making applications. When night temps begin to fall into the 30s, plants initiate carbohydrate movement into the root system. This increases the movement of herbicide into roots to increase weed kill. Combination herbicides are generally more successful than individual active ingredients in controlling perennial broadleaf weeds.